>>5470463I have the Menasor PE sets. I think it makes it look better, but it's a trade off.
You gain a more stable overall combiner, but lose the waist articulation. But given the OTHER combiners don't have any waist articulation, that may or may not bother you. The Motormaster/Optimus mode knees then become your thighs and hip joints effectively, so if yours happen to have weak knees there, it might be a disaster. Mine are fine though, so I'm good with it.
He has about the same poseability all around minus the hip joint, and also is a bit taller due to the legs being longer, but he'll have a natural "A" stance now and you can't really put his legs in or out too far without using the Motormaster knees. It's not difficult and I'm probably describing it poorly.
I think it was worth it. Especially if you're getting one of the Optimus sets, since they're cheaper and come with the hands/feet while the MM set was seperate.